The purpose of this project is to demonstrate the effectiveness of intervention methods in changing behaviors that place IVDSs and their sexual partners at risk for AIDS. The project will determine the effectiveness of different counseling interventions in changing risk behaviors of IVDAs and their sexual partners, drawn from the major ethnic populations represented in Tucson and Nogales, AZ (Hispanics, non-Hispanic, Whites, Native Americans and Blacks). In addition to evaluating intervention strategies in changing risk behaviors, attitudes, beliefs and knowledge about AIDS, the project will also determine seropositivity rates in the specified target populations. Currently, these targeted metropolitan areas represent a high level of intravenous drug abuse but a low level of diagnosed cases of AIDS. Subjects will also be monitored over the duration of the project (maximum 18-month follow-up) to determine maintenance of change over time. Using five outreach modalities (street, treatment waiting lists, criminal justice, health systems and sexual partners), 2700 subjects consisting of IVDAs and their sexual partners will be identified, contacted and randomly assigned to either a Standard AIDS Intervention (AIA interview, risk assessment, basic AIDS information, pre/post test counseling, referral if appropriate and AFA interview) or and Intensive AIDS Intervention (Standard Intervention components plus weekly individual and group counseling sessions for three months focused on learning behavior modification skills). Standardized training will be provided for all appropriate project staff and staff in cooperating community agencies. The process evaluation will evaluate the effectiveness of specific procedures while the outcome evaluation will compare differential effectiveness of the intervention levels for specific subpopulations. The AIA and AFA developed by NIDA will allow for the addition of this project's data to the national evaluation across projects.